Nationality: United StatesExecutive summary: Surveyor of the Mississippi basin

The American explorer Jean Nicholas Nicollet was born in Cluses, Savoy on 24 July 1786. He was educated at the college in his native place, and in 1805 became assistant in mathematics in Chambery. Later he went to Paris, where in 1817 he became secretary and librarian of the observatory, also studying astronomy with Laplace, who refers to Nicollet's assistance in his works. In 1823 he was given an appointment in the government bureau of longitudes, at the same time holding the professorship of mathematics in the College of Louis le Grand, and the post of examiner of candidates for the naval school. In 1832 he came to the United States for the purpose of acquiring an extended knowledge of the physical geography of North America. After exploring the southern states he studied the great basin that is embraced by the sources of the Red, Arkansas, and Missouri rivers, and in 1836 extended his investigations to the sources of the Mississippi. He determined, by astronomical and barometrical observations, the geographical position and elevation of many important points, also collecting many interesting details respecting the history and dialects of the Indian nations, and the productions and natural history of the country. On his return to Washington he was engaged by the War Department to visit the far west and prepare a general report and map for the government. Lieutenant John C. Fremont was detailed to accompany him as assistant. In 1841 he presented a paper on "The Geology of the Upper Mississippi Region and of the Cretaceous Formation of the Upper Missouri" before the Association of American geologists and naturalists, and in 1843, at the Albany meeting of this association he gave further particulars respecting the cretaceous formation, and exhibited the beautiful map of the country that he had completed for the government. He published Cours de mathematiques l'usage de la marine with M. Reynaud (Paris, 1830), and Report intended to illustrate a Map of the Hydrographical Basin of the Upper Mississippi River (Washington, 1843.) He died in Washington, DC on 11 September 1843.